The present invention relates generally to a sealing device to establish a seal between a partition and at least one cable or a conduit passing through a hole in said partition. The invention more particularly concerns a sealing device of the type comprising two half-shells adapted to be placed on the cable or conduit and assembled with each other to form together a cylindrical body which completely surrounds said cable or conduit and can be secured to said partition through the hole in the latter, a sealing joint adapted to be disposed between the cylindrical body and said partition, and sealing means to fill the space between said cable or conduit and said cylindrical body and to immobilize these relative to each other.
There is already known a sealing device of the type described above, adapted to establish a seal between a partition and a bundle of cables passing through a hole in said partition. In service, to establish a seal with said known sealing device, the two half-shells are placed about the bundle of cables and secured to each other by adhesive strips. Then, two conical cups, slotted longitudinally on one side and made of a flexible material, are disposed about the bundle, each on one side of the cylindrical body formed by the two half-shells, so as to cover the open ends. Once emplaced, each conical cap is maintained closed and assembled to the cylindrical body also by the adhesive strip. There is thus obtained a xe2x80x9cmoldxe2x80x9d into which can be injected a filling product which polymerizes at ambient temperature and which serves as the sealing means to fill the space between the bundle of cables and the cylindrical body. At least one injection opening is provided in at least one of the half-shells of the cylindrical body for the injection of the filling product. After polymerization and drying, the two conical cups are removed.
This known sealing device has a certain number of drawbacks. The quality of the sealing obtained is haphazard. It thus depends largely on the care with which the xe2x80x9cmoldxe2x80x9d is filled and on the quality of the filling product to fill the spaces between the various cables of the bundle of cables. Moreover, the preparation time of the sealing device is relatively long, particularly because of the time necessary for polymerization of the filling product. Still further, the filling product is generally toxic and requires precautions during its use. Finally, the sealing device cannot be repaired in case of a leak.
The present invention therefore has for its object to provide a sealing device of the type indicated above, whose preparation will be easier and more rapid than that of the known sealing device, whilst obtaining a good seal, without the use of a toxic filling product, and which permits repairs if needed.
To this end, the sealing device according to the invention is characterized in that the sealing means comprise:
a) at least one sealing gasket of an elastomeric material capable of flowing, and adapted to be disposed about said cable or conduit;
b) a radial gripping device, in the form of a resiliently deformable split ring, which is so dimensioned as to be able to fit about said sealing gasket and to engage in said cylindrical body, and which comprises a skirt structured or configured to be radially retractable at least substantially uniformly about its entire circumference under the action of an axial gripping force; and
c) an axial gripping device which interacts with said cylindrical body and said skirt to require the latter to retract so as to compress and cause said sealing gasket to flow to fill said space between the cable or conduit, and the cylindrical body.
Preferably, the sealing device according to the invention can also have the following characteristics:
the radially retractable skirt of the radial gripping device is defined by a circular series of flexible fingers, which are formed from a single piece with said split ring and extend from a surface of the latter in a direction substantially parallel to the axis of said split ring;
the flexible fingers have their lateral surfaces, two by two facing each other, which are inclined so as to overlap in the circumferential direction of the split ring;
the cylindrical body is provided with a screwthread at one of its ends and, in a region located at a distance from said screwthread, an annular internal shoulder serving as an axial bearing for the split ring of said radial gripping device;
the axial gripping device comprises at least two pieces assembable together, which define, after their assembly, a conical surface and a screwthreaded element adapted to coact with the screwthread of said cylindrical body to press axially said conical surface against the free ends of the flexible fingers of said radial gripping device, so as to require said free ends of the flexible fingers to retract radially;
the screwthread of said cylindrical body is a female thread and said axial gripping device comprises three pieces, namely a split collar of resiliently deformable material, which can slide axially in said cylindrical body and whose central hole has, as a cylindrical surface, a conical bevel turned toward the flexible fingers of said radial gripping device, and two half-nuts assembled together to form together an externally screwthreaded sleeve-nut, which surrounds said cable or conduit, is screwed in the female screwthread of said cylindrical body and presses axially said split collar and its conical bevel against the free ends of the flexible fingers of said radial gripping device to make them retract radially;
the split collar comprises, in its region diametrically opposed to its slot, a groove which is parallel to said slot and which defines in said region a zone of lesser wall thickness facilitating resilient deformation of said split collar for its emplacement about said cable or conduit;
the two half-nuts are assembled to each other by surfaces that are mutually in contact, which have respectively male and female positioning elements receivable in each other and clip retaining means;
said sleeve-nut comprises on its peripheral surface a mark which is indicative of insufficient gripping of said sleeve-nut when the latter is screwed into the female screwthread of said cylindrical body and said mark is still visible;
the mark is constituted by a colored ring which has a color different from that of the rest of the sleeve-nut;
the sleeve-nut and the cylindrical body comprise, by way of anti-unscrewing means, at least one protuberance and at least one recess which engage in each other when said sleeve-nut has reached a predefined degree of screwing;
the cylindrical body and the split ring of the radial gripping device comprise at least one protuberance and at least one recess engaging in each other as an anti-rotation device;
the two half-shells forming said cylindrical body are assembled to each other by mutually contacting surfaces which have male and female positioning elements, and are maintained assembled with each other by bolt-nut assemblies;
the bolts and the nuts of the bolt-nut assemblies are disposed in recesses respectively provided in the two half-shells and are maintained there by retaining elements which are formed in said recesses, of a single piece with said half-shells;
as the sealing gasket, there is provided a sleeve of elastomeric material which is longitudinally slotted and which covers the internal surface of the split ring of said radial gripping device, including its flexible fingers, said elastomeric sleeve comprising, at one of its ends, a small collar which covers the surface of said split ring oriented toward the annular internal shoulder of said cylindrical body and an adjacent portion of the external peripheral surface of said split ring;
as a sealing gasket, there is provided in addition to said sleeve of elastomeric material, at least one pair of strips of elastomeric material which are disposed as a sandwich and pressed on each side of a layer comprised by at least one portion of said cables forming said bundle.
in the case of a single layer formed by all the cables of said bundle, the sandwich composed of said layer and the two strips of elastic material is rolled up on itself so as to form a roll whose axis is parallel to the longitudinal axis of the cables, and an additional strip of elastic material is wound in at least one turn about said roll;
in the case of several layers each formed by a certain number of cables of the bundle and each gripped in sandwich fashion between a respective pair of strips of elastomeric material, said layers covered by their strips of elastomeric material are superposed on each other, and an additional strip of elastic material is wound in at least one turn about the assembly formed by the superposed layers;
each of the two half-shells forming said cylindrical body is provided with a half-flange which, after assembly of the two half-shells, forms with the half-flange of the other half-shell a flange for the securement of said cylindrical body to said partition;
the two half-flanges and the annular shoulder of said cylindrical body are co-planar;
the sealing joint is constituted by two half-joints of elastomeric material each associated with the half-flange of a corresponding half-shell, each half-joint comprising a substantially flat portion, in the form of an arc, which is adapted to be applied against the surface, on the partition side, of the half-flange of the corresponding half-shell, and two portions located respectively at the base of the portion in the shape of an arch and adapted to be interfitted between the two half-flanges and between the corresponding portions of the half-shells forming together said annular shoulder of the cylindrical body;
a substantially flat portion of each half-joint is fixed to the half-flange of the corresponding half-shell by bolting;
at least one of the two half-shells of said cylindrical body comprises, over the thickness of its wall, at least one longitudinal channel, of which one of the ends opens to the exterior of said cylindrical body on the side of its screwthreaded end and is closed in a sealed manner by a cable grommet of elastomeric material, and whose other end opens into the internal space of said cylindrical body beyond its annular shoulder;
the body is at least superficially electrically conductive and has, at each of its ends, a circular throat for the securement of one end of a metallic braid for armoring the cable or a bundle of cables with the help of a gripping collar.